Tubing caliper



March 6, 1.951 D. B. MCMAHAN TUBING CALIPER Fiied July 5, 1945 4 Sheets-Sheet 1 uff/077??? D. B. MCMAHAN TUBING CALIPER March 6, 1951 4 Sheets-Sheet 2 Filed July 5, 1945 D. B. MCMAHAN March 6, 1951 TUBING CALIPER 4 Sheets-Sheet 3 Filed July 5, 1945 j?? v for zfrwa/u. Mij/ga?? March 6, 1951 'I D. lB. MGMAHAN TUBING CALIPER Filed July 5, 1945 4 Sheets-Sheet 4 Patented Mar. 6, 1951 TUBING CALIPER Durward B. McMahan. Duncan, Okla., assignor, by mesne assignments, to M. M. Kinley and Jack Kinley, Houston, Tex.

Application July 5, 1945, Serial No. 603,285

s claim. (ci. ca -11s) This invention relates to recording calipers, and more particularly to mechanical means for measurng and recording the variations in internal diameter of pipe such as tubing or casing used in oil wells.

Pipe such as tubing used in oil wells sometimes becomes corroded or eroded by the passage of gas or liquid therethrough. In deep gas wells, for example, the tubing through which the gas flows may become weak in spots due to corrosion or erosion. This weakening usually occurs close to the collars which join the sections of pipe to,

gether, but is apt to occur anywhere and does not follow any set rule or denite pattern. Heretofore it has been the common practice to pull the tubing in such wells periodically and make an inspection visually or otherwise at the surface of the ground, but it has occasionally happened that the tubing has become so Weakened that its parts when at attempt is made to pull it.

In accordance with the present invention it is proposed to provide a recording caliper which will measure and make a record of the condition of tubing or other pipe such as that used in wells so that information can be obtained which will indicate the rate of corrosion or erosion at an?,1 given point and will enable the operator of the well to know when the tubing should be pulled before there is danger of parting.

In accordance with the present invention the device is run through the pipe or tubing. If used in a well it is lowered on a measuring line or other ilexible connector and is caused to make a record of variations in internal diameter of the pipe as it is being pulled out of the well. Various features of the invention are of utility in recording variations in internal diameter of pipe at the surface of the ground such as pipe lines and if the device is so used, no measuring line would be necessary if the device is pumped through the line. It seems obvious that where fluids are pumped under pressure in pipe lines or where pressure is prestnt in a well, suitable packing is used to prevent leakage or loss of fluid. Generally a device called a casing head is employed at the top of a well, which is adapted to permit flowing of the well when desired but which retains the Well under control. Such a device for this purpose is shown in the patent to G. H. Ennis issued on April 20, 1943, and bearing Number 2,317,039. The instant invention is of course operated on a flexible conductor through such casing head when the device is used on well pipe in situ and Where such well has a pressure therein.

While the apparatus of the present invention is capable of recording some information as to longitudinal slots or other defects in pipe, it is particularly designed to record information as to the change in contour of the cross-sectional area inside pipe, and is particularly designed to record variations in the internal diameter of pipe caused by gas flow therethrough. If pump rods cause wear inside the tubing in an oil well, slots are formed in the tubing by the rods. However, where gas is flowing through tubing the pipe does not usually become weakened due to the formation of slots, but turbulent iiow or other factors cause the tubing to become weakened at one or more places, the corrosion or erosion occurring more or less radially at a given place and enlarging the diameter of the pipe more or less uniformly. It is the enlargement of the internal diameter of pipe such as that caused by gas flow which the apparatus of the present invention is particularly designed to measure and record.

Accordingly, it is an object of the present invention. to design a self-contained recording caliper adapted to be run through pipe and make a record of variations in the internal diameter thereof.

It is a further object of the invention to deF vise novel means for driving a recording chart or tape mounted in a body adapted to be moved through pipe such as that used in oil wells, the chart being driven in proportion to the move= ment of the body through the pipe.

Y Other objects and advantages reside in eertain novel features of the arrangement and construction of parts, as will be apparent from the following description taken in connection with the accompanying drawings, in which:

Figure 1 is a vertical cross-sectional view of a part of a gas well showing apparatus constructed in accordance with the present invention located in the tubing therein;

Figure 2 is a, perspective view of ythe lower portion of the recording caliper shown in Figure l;

Figure 3 is a transverse cross-sectional view of the recording caliper shown in Figure 1, the view being taken on the line 3-3 thereof;

Figure 4 is a cross-sectional view taken through the metering head of the apparatus of Figure 1, the view being taken on the line 4 4 thereof Figure 5 is a vertical cross-sectional view of the lower portion of the apparatus of Figure l;

Figure 6 is a vertical cross-sectional view of the intermediate portion of the apparatus shown in Figure l and illustrating the gear train and other mechanism for driving the recording chart or tape and of the mechanism for actuating the stylus which makes a record on the tape and also showing locking means for holding the stylus in xed position while the apparatus is being lowered into a well;

Figure '7 is a fragmentary side view of the apparatus shown in Figure 6 and showing particularly the locking mechanism for holding the stylus and for holding the metering head in inoperative position while the apparatus is being lowered into the well;

Figure 8 is a-vertical cross-sectional view of e upper portion of the apparatus shown in Figure 1 and particularly illustrating the con struction of the metering head;

Figure 9 is a fragmentary side view of the recording apparatus shown in Figures 6 and 7 together with the gear train for driving the same;

Figure 10 is an enlarged cross-sectional view of the recording apparatus shown in Figure 9; and g Figure l1 is a plan view of an actual record y obtained with the apparatus shown in Figures 1 to 10, inclusive, together with an interpretation of the record.

Referring to the drawings in detail, and rst to the complete assembly shown in Figure 1, it will be seen that the casing of a gas well is there illustrated at l2, the well being provided with a tubing-@i3 through which gas is being produced.

In accordance with the present invention a flexible connector or line |4 is used to lower an elongated cylindrical body I5 into the well. At its lower end the body I5 may be provided with a tapered nose |6`and at its upper end it may be provided with a suitable fishing neck I1 and with a jar I8.

The elongated cylindrical body I5 contains recording apparatus driven by a drive wheel I9 and it is provided with a metering head 2| which when the apparatus is in operation to caliper the tubing, controls movement o1' a stylus in the recorder.

At the lower end of the body Iiiv near the nose I6 a yieldable centering arrangement is provided. This is shown in cross-section in Figure 3 and may consist of the drive wheel I9 adapted to ride along one side of the tubing and two spring pressed balls 23 spaced 120 degrees from the drive wheel I9. The balls 23 and the springs 24 cooperating with them may be mounted in suitable cylindrical housings 25 held in place by screws 26 as shown in Figure 3. Any other suitable centering means such as drag springs might be used without departing from the spirit of the invention.

As shown in Figures l and 2 the wheel I9 which drives the recording chart or tape is mounted in the body I5 immediately above the centering balls 23. As shown in Figures 2 and 5 the drive wheel I9 is mounted upon an arm 21 pivoted on a shaft 28 located within the tubular body I5. A coil spring 29 (Figure 5) urges the arm 21 tothe left asjrewed in Figure 5 and causes the wheel I 9 to e'frgage the tubing I3. An adjustable stop Sdilfnits movement of the arm 21.

The drive wheel I9 is provided with a knurled or roughened surface so that as the body I5 is moved through the tubing I2 the wheel I9 will be rotated. The shaft 3| upon which the wheel I9 is mounted is provided with a bevel gear 32 in mesh with a companion bevel gear 33 secured to a flexible shaft 34 which is in turn connected by coupling 35 to a rotating shaft 35. extending through a gland 31 into the interior of the Y recorder housing.

The recorder housing consists of a tubular casing 38 connected to the body I5 by a coupling member 39 (Figure 5) at its lower end which contains the gland 31. The casing 38 has a similar coupling member 40 (Figure 8) at its upper end, which contains a gland 4| through which a longitudinally movable rod 42 extends, which rod actuates the stylus of the recorder.

The metering/head 2| contains mechanism which when the apparatus is in operation to record variations in diameter of the tubing I3 moves the rod 42 up and down in proportion to variations in diameter of the tubing. This metering head is shown in vertical cross-section in Figure 8 and in transverse cross-section in Figure 4. As shown in these figures, the arrangement includes a member 43 having the general shape of a truncated cone secured to the rod 42 and mounted for movement longitudinally of the metering head 2 I The reciprocal means or member 43 is provided with a guiding spindle 44 extending up into a bearing 45 screw threaded into the top of the metering head 2|. A coil spring 4B abuts against the top of the member 43 and against the bottom of the bearing 45 so as to urge the member 43 downwardly at all times.

By means which will be described hereinafter, downward movement of the member 43 may be prevented while the apparatus is being lowered into the Well but when the arrangement is in calipering or operating position downward movement of the member 43 is limited only by radial movement of the feeler members shown as three balls 41 mounted in the metering head so as to engage the conical surface of the member 43, the balls thus serving as feelers which move the member 43 in accordance with the variations in internal-diameter of the pipe I3. The balls 41 are shown spaced circumferentially of the metering head 2|, 120 degrees apart, but it is not necessary that this exact spacingbe employed.

The balls 41 are held in place on the metering head by means of plates 48 held by screws 49. It will be obvious that there is sufficient play in this mounting to permit the balls to move in and out radially depending upon variations in diameter of the tubing |3 with which they are in contact as shown in Figure 4 when the calipering operations are being performed.

The taper of the conical surface of member 43 is such that the balls 41 tend to lift it against the action of Ithe spring 46 when the assembly passes from a section of the tubing having a large diameter into a section having a small diameter. An angle of 42 degrees with respect to the center line of the rod 42 has been found tc be a satisfactory taper for the conical surface of member 43.

It will be apparent that since three balls 41 are provided each will be in contact with the wall of the tubing or pipe being measured and that this arrangement serves to permit movement of the tool to accommodate eccentric or noncircular sections of the tubing, the metering head being located some distance vertically above the centering arrangement provided by the balls 23 near the bottom of the tool.

As mentioned above, the rod 42 extends through a gland 4| into the recorder housing 38. The gland 4| may have its packing under spring tension provided by the coil spring 50 and the disk and a rubber stopper 62 may also be provided to insure against the leakage of any fluid into the recorder housing. Chevron packing 53 may be provided as illustrated adjacent the threads on the cylindrical housing 36 and on the coupling ,held against radial movement by a release pin 51 mounted for radial movement in a slot 59 in the depending guiding sleeve 59 of the coupling member 4|). When in locked position outward movement of the release pin 51 is prevented by a ratchet disk 66 which is provided with a slot 6| as shown in Figure 7. When the disk 66 is rotated to the proper position the release pin 5l may enter the slot 6|, whereupon the ball 56 also may move radially and permit longitudinal movement of the plunger 54. The disk 66 may be rotated clockwise as viewed in Figure 7 by means of the ratchet pawl 62 mounted on the lever 63 actuated by the connecting rod 64. A second pawl 65 prevents counter-clockwise movement of the disk 66.

It will be observed that the disk '60 has ratchet teeth only over a portion of its periphery, there being a section adjacent the slot 6| which has no teeth. When the disk is turned into the position about 180 degrees from that illustrated with the blank section under the pawl 62, further reciprocatory movement of the connecting rod 64 will not rotate the disk 60. Thus, when the disk 66 is rotated to 'permit movement of the release pin 51 it stays in the released position until manually reset. As long as the plunger 54 is held in the locked position as shown in Figure 6 the member 43 shown in Figure 8 cannot movewith respect to the body of the tool. In this position the member 43 may be out of contact with the balls 41 and the device may be lowered into the Well freely without the balls 41 contacting the walls of the tubing. However, when the locking means provided by the ball 56 and release rin 51 permits the plunger 54 to move downwardly the member 43 engages the balls 41 and further downward longitudinal movement under the action of the spring 46 is limited in varying amounts, depending upon the internal diameter of the pipe or tubing in which the device is located, due to the action of the balls 41.

To make Va record of the movement of the plunger 54 after it is released, and thus make a record of movement o i the member 43 which is proportional to variations in the internal diameter of the tubing being calipered, a floating anvil 66 is provided immediately beneath the plunger 54. This anvil may be provided with an adjustable abutment 61 for engagement with the bottom of the plunger 54 and it is urged upwardly by a coil spring 6-8 and is mounted for longitudinal movement in the frame plates 69.

The frame plates 69 as shown in Figures 6, '7 and 9 may be secured Iat one end to the coupling member 40 and at the other end to the one way clutch mechanism to serve as a framework for mounting reels and driving mechanism for a tape or recording chart and also serve as means for mounting the recording stylus. As best shown in Figure 10, the recording tape 19 travels from a supply spool 1I under a guide roller 12 across' the recording base 13, under a driving roller 14 and onto the receiving spool 15. A spring pressed idler pulley 16 is provided to keep the tape in contact with the driving roller 14. Two styluses are provided for making marks upon the tape 16. One of these, shown at 11 is held in fixed position and merely makes a mark upon the tape which serves as a base line for indicating what the internal diameter of the tubing or pipe being calipered should be. The other stylus shown at 18 is mounted on a bell crank lever 19 pivoted on a cross member secured to the plates 69. By means of a connecting rod 8| the bell crank lever 19 is connected to the anvil 66 so that the stylus 18 is moved back and forth across the tape 16 in response to movement of the anvil I66 and in accordance with variations of movement of the member 43 depending upon variations in the internal diameter of the tubing being callpered, as explained above.

The driving roller 14 for the tape 16 is driven through a gear train connected to the rotating shaft 36 entering the recorder housing at its lower end through the coupling member 39, as explained above. The train of gears is shown as consisting of gear wheels 82, 83, B4, 35, 66, 66 and 89, the gear wheel 82 being xed to the shaft which mounts the driving roller 14, while the gear 89 is mounted on a. shaft which is driven by a worm gear 99 connected to a longitudinally disposed shaft 9| mounted in -a ball bearing 92 at the lower end of the frame plates 69. The shaft 9| is connected by a one-way clutch to a shaft 93 coaxially mounted with it in a ball bearing 94. The oneway clutch is provided by means of the tightly fitting coil spring 95 mounted on the two shafts 9| and 93 with one end being secured to the shaft 9|. Beneath the bearing 94 the shaft 93 is provided with a clutch jaw 96 adapted to make'connectiori with a similar clutch jaw 91 (see top of Figure 5) which is secured to and driven by the shaft 36. The clutch jaws 96 and 91 are held in engagement by a coil spring 98. The clutch provided by the jaws 96 and 91 serves as means for quick assembly and disassembly when a recording apparatus is placed in or removed from the device. As shown in Figure 5, the shaft 36 is provided with suitable ball bearings near its upper end and it is provided with means for maintaining a tight seal around it similar to that described above in connection with the sealing means for the shaft 42.

The locking means shown at the top of Figures 6 and '7 for controlling movement of the plunger 54 yas described above, is operated to release the plunger 54 automatically upon a predetermined amount of upward movement of the device through tubing being calipered. This automatic operation is brought about by connecting the rod 64 which drives the disk 66 to an eccentric 99 mounted on the same shaft as the driving roller 14 for the tape. -Since the driving roller 14 is driven only in one direction by the driving wheel I9 and the means for transmitting motion from the wheel i9 to the roller 14, there is no rotation of the disk 60 until Athe calipering device is moved upwardly through the tubing, it being understood that the roller 14 does not rotate when the device is being lowered into the well because of the one-way clutch arrangement provided by the spring 95. When the roller 14 begins to move the tape 10, however, rotation of the eccentric 99`be8ins to actuate the ratchet pawl 62 and rotates the disk 00 to release the plunger 54. Thus, after a predetermined amount of upward movement oi the device through the tubing the locking means releases the plunger 54. Likewise, after a predetermined amount or upward movement of the device through the tubing the stylus 18 begins to move back and forth, for until the plunger I is released the coil spring 60 holds the anvil '66 in fixed position at the upper end of the slots provided in the frame plates To keep the tape being wound upon the receiving spool reasonably taut and yet permit some slippage between it and the driving roller 14 a spring belt |00 connects its shaft to the shaft upon which the driving roller 1I is mounted. i y

In Figure 11, contiguous sections oi' a recording paper tape made with the apparatus shown in Figures 1 to 10, are illustrated at |0|, |02, |03, |04, |05, |06, |01 and |08. On these sections of the tape 4the straight line approximately down the center as shown at |09 is that made by the stylus 11, while the wavy line shown at ||0 is that made by the stylus 18, and records variations in diameter of tubing which was being calipered.

It will be observed that in some places the tubing was of smaller diameter than it was supposed to be, whereas in other places due to corrosion or erosion or to other causes it was of an internal diameter considerably greater than it was supposed to be. Other variations such as collars, pitting and mill wrinkles are plainly indicated on the graph and are so marked on Figure 11.

While only one embodiment of the invention has been shown and described herein itis obvious that various changes may be made without departing from the spirit of the invention. For example, while the recording means has been shown as consisting of a paper tape, it is obvious that photographic lm could be used, and it is further obvious that instead of the use of a stylus other tracing means such as a light beam might be used for making the record. Also other means than the gear train specically illustrated and described might be used to transmit motion from the wheel I9 to the roller which drives the recorder.

Other changes will be apparent to those skilled in the art without departing from the spirit of the invention or the scope of the annexed claims.

I claim:

1. In a recording caliper adapted for use in measuring the inside diameter of pipe in a well, the combination comprising an elongated cylindrical body adapted to be run inside the pipe, a recording chart in said body, a stylus mounted in said body for relative movement with respect to said body and with respect to said chart for making a graph on said chart, a spring pressed wheel carried by the body for engaging the interior of the pipe, a mechanism including a one-way driving device for effecting said relative movement to represent the position of said body in the pipe only when said body is moved upwardly through the pipe, a metering head carried by said body, a movable member thereon, locking means for preventing movement of said movable member while said body is being lowered down through the pipe in the well, a connection to said locking means for mechanically releasing said member upon a predetermined amount of movement of said body through the pipe in the upward direction, means for moving said member, afterthe locking means has released the same, in accordance with variations in internal diameter of said pipe, and means to move said stylus in proportion to movement of said member.

2. In a recording caliper adapted for use in measuring the inside diameter of pipe in a well, the combination comprising an elongated cylindrical body adapted to be run inside the pipe, a recording chart in said body, a spring pressed Wheel carried by the body for engaging the interior of the pipe, a stylus mounted in said body for movement with respect to said body and with respect to said chart for making a graph on said chart, and a mechanism including a one-Way drive for allowing said movement only when said body is moved in one direction through the pipe, a metering head carried by said body, a member mounted as part of said head for movement longitudinally of said body, a spring for urging movement of said member in one direction, and contact means so mounted as to limit movement of said member in that direction in varying amounts depending upon the internal diameter of the pipe, locking means for said metering head to prevent movement of said member therein while said body is being lowered down through the pipe in the well, a release for said locking means, aconnection therefrom for mechanically releasing said member upon a predetermined amount of upward movement of said body through the pipe, and connecting means from said member for causing said stylus to move in proportion to movement of said member after said locking means has been released.

3. In a recording caliper adapted for use in measuring the inside diameter of pipe in a well, the combination comprising an elongated cylindrical body adapted to be run inside the pipe. a recording chart member in said body, a stylus member mounted in said body for movement with respect to said body and with respect to said chart for making a graph on said chart, drive means carried by the body for engaging the interior o1 the pipe and a connection from said drive means to one of said members for causing relative movement between said members and to represent movement of the caliper in the well only when said clutch drives as the caliper is moved in one direction through the pipe, a metering head carried by said body and having a reciprocal member mounted for movement longitudinally of said body, a spring for urging movement of said member in one direction, and contact means so mounted as to limit movement of said member in that direction in varying amounts depending upon the internal diameter of the pipe, locking means for said metering head to limit movement of said member while said body is being lowered down through the pipe in the well, said locking means for said metering head including a locking pin and a mechanical eccentric linkage operable by said drive means to release said reciprocal member upon upward movement of said body through the pipe, and means for causing said stylus to move in vproportion to movement of sai-:i metering head after said locking means has released the same.

4. In a recording device adapted for use in oil wells or the like, a housing, a chart member located therein, a stylus member for tracing a graph on said chart, drive means for actuating one of said members in proportion to movement of said housing in one direction in the well while not actuating the same when said housing is moved in the opposite direction in the well, and

means for locking said stylus member in position while said housing is moved in such opposite direction in the well, said drive means including, a wheel to engage the wall of the well and rotate as the housing is moved in either direction in the well, a shaft connected to said wheel for rotation thereby, 4said shaft extending in said housing, and a one-way clutch connecting said shaft to actuate one of said members only when said housing is moved in the one direction in the well, said locking means for said stylus member including a locking pin and a mechanical pivoted eccentric operated by -said drive means to release said locking pin upon upward movement of said housing in the well.

5. In a caliper adapted for measuring and recording variations in the inside surface of a pipe. the combination of a metering head, a movable member thereon, mechanism contacting the inside pipe surface for causing said member to move in accordance with variations of the internal surface of the pipe, locking means for holding said movable member in an inoperative position while said caliper is moved in one direction in the pipe, a one-way release means for mechanically releasing said locking means upon movement of said caliper in the other direction, said releasing means including a member projecting to engage the interior of the pipe,A said locking means including a locking pin, and said releasing means also including an actuating means connected from said projecting member and to said pin, and further including a one-way drive therefor.

6. In a caliper tool to determine variations in the inside surface of a pipe in a well bore, a reciprocal means carried by the tool and movable as a function of the pipe surface variations, a locking device to h'old said means immovable when the tool descends in the well pipe, feeler members projecting from the tool to contact the pipe surface variations, said feeler members being mounted to move said reciprocal means as a function of the feeler movement, another member also projecting from said tool to engage the pipe and to be thereby moved relative to the tool upon upward travel of the tool, a connection from'such other membell to move said locking device, a spring to thereupon maintain said reciprocal means in contact with said feeler members, a record mechanism in said tool including a recorder member, and a recording member, a connection from said reciprocal means to said record mechanism so that one of said members will be moved as a function of such surface variations.

7. In a caliper for measuring and recording surface variations inside of a pipe in a well bore, a metering head including a plurality of movable members contacting the pipe surface to be calipered, said head also including a mechanism for operation by such members in accordance with the surface variations, a locking means for said mechanism when the caliper moves in one direction in thewell pipe, another member projecting laterally from the caliper and also contacting the pipe suface, a one-way connection driven from said last member to said lockingmeans to release said locking means as a function of upward movement of the caliper so that said rst members and 'mechanism will operate to effect measuring and recording'.

8. In a recording device adapted for use in measuring surface variations of pipe in oil wells or the like, a housing, a chart member located therein, a stylus member to mark said chart member,"drive means for driving one of said members in proportion to movement of said housing in one direction in the well means for moving the other member in response to said variations, said drive means including a spring pressed arm pivoted to said housing, a wheel adapted to engage the wail of the weil and rotate as the housing is moved through the well, a shaft connected to said wheel for rotation thereby and extending in said housing, and also including a one-way clutch connecting 'said shaft to one of said members whereby one of said members will be actuated only when said housing is moved through the well in one direction, a locking means for said stylus member, and a release therefor including a device adapted to be pre-set for operation on upward movement of the recording device in the well.

DURWARD B. McMAI-IAN.

REFERENCES CITED The following references are of record in the file of this patent:

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